Ok I have found another problem...

I have these two characters set up wit one spotlight illuminating from top. What I am trying to do is having just the one in the front in focus. The camera settings are all the defaults maya gave to it when it was created. (Just the film gate was set to 35mm full aperture)
The head up display shows that the distance to the camera of the foreground character is 7.917 units. F Stop is 5.6 Focus region scale 1.0.
With focus distance set to 7.917 the IPR render looks like pic1.
The same settings but f stop to 25 doesn't make a change. And f stop to maximum moves the blured ara up about 2 millimeters. Putting the f stop to 0 blurs the image completely
Why does the camera only focus the legs and what would I have to do to get the focus right?
Thanks in advance for any help given